Reversing mechanism.



.H. E. TOWNSEND.

REVERSING MECHANISM.

APPLICATION rum) MAY s, 1913.

Patented; Feb. 23, 1915.

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H. E. TOWNSEND.

REVERSING MECHANISM.

APPLIOATION FILED MAY 8, 1913. L1 Wfimu. Patented Feb. 23, 1915.

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EEVERSING MECHANISM.

APPLIOATIOIfI FILED MAY B, 1913.

Patented Feb. 23, 1915.

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H. E. TOWNSEND.

REVBBSING MECHANISM. APPLICATION FILED MAY s, 1913.

Patented. Feb. 23, 1915.

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E. TOWNSEND, OF EAST PROVIDENCE, ODE ISLAND, ASSIGNOR TO BROWN WACTURING 00., 0F PROVIDENCE, RHODE IND, A CORPO l MON REVERSING MECHANISM.

Patented Feb. as, rare.

Application filed may 8, 1913. Serial No. 786,335.

To all whom it may concern." A

Be it blown that I, HERBERT E. Townsnnn, a subject of the King of Great. Britain, residing at East Providence, in the county of Providence and State of Rhode Island, have invented certain new and use ful Improvements in Reversing Mechanisms; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to reversing mechanism for grinding or other machines, and more particularly to a reversing mechanism of the load and fire type. Reversing mechanisms of this character as heretofore constructed have usually been provided with two springs, one of which is compressed and released to shift the clutch or other reversing device in one direction, and the other of which is compressed and released to shift the clutch in the opposite direction. With this construction comparatively short springs must be used if the mechanism is to have the desired compactness or is to be arranged within the limit of spacewhich may be available. 7

It is the object of the present invention to provide a novel and improved mechanism in which a single spring maybe utilized in shifting the reversing device in opposite directions, thereby enabling the use within a compact and limited space of a longer and consequently more durable and efiicient spring than has been practicable with the former two-spring construction.

To this end the invention comprises the features of construction and combinations of parts hereinafter described and set forth in the claims.

The various features of the invention will be readily understood from an inspection of the accompanying drawings and the'following detailed description of the mechanism illustrated therein.

In the drawings Figure 1 is a front elevation showing the front plate and the reversing mechanism of a grinding machine; Fig. 2 is a transverse sectional elevation showing the parts illustrated in Fig. 1; Fig. 3 is a sectional front elevation showing the reversing mechanism; Fig. 4 is a sectional view on line 44:, Fig. 3; Fig. 5 is a detail plan view showing the parts illustrated in Fig. 3; and Fig. 6 is a partial front elevatron of the parts shown in Fig. 5.

In the drawings, the invention is illustrated as embodied in a grinding machine of the well-known type in which the work supporting table is reciprocated and is autom'atrcally reversed at the end of its travel 1n elther direction by reversing mechanism operated by adJustable dogs carried by the table. As shown, the work supporting table, which is indicated at 1, is mounted on ways, one of which is indicated at 2, andis moved longitudmally on the ways through a shaft 3 which is connected with the table through gearlng 4: and a rack 5. The shaft 3 is driven in one direction or the other by one or the other of two bevel pinions 6 and 7 engaging a bevel gear 8 secured to the shaft. The pinions are mounted to turn freely in thelr bearings and are provided with clutch members 9 and 10 arranged on opposite sides of a reversing clutch 11. The clutch isconnected Wlthlfl longitudinally movable driving shaft 12 by a pin 13 which passes through the shaft and clutch and through slots formed in a sleeve 14 surrounding the shaft and interposed between the hubs. of

effected by shifting the clutch from one clutch member to the other.

It Is lmportant that the reversin clutch or other reversing device of a grinding mathe bevel pinions. During the operation of v chine be instantly shifted in reversing the 5 movement of the carriage or work table, and a mechanism for accomplishing this result which embodies the present invention in its preferred form is embodied in the machine illustrated, and is connected to shift the reversing clutch as the work table reaches the end of its movement in either direction. As shown, this mechanism comprises a clutch shifter in the form of a frame 16 which is provided with a yoke 17 engaging the groove 18 in the clutch, and is also provided with two hubs 19 and 20 mounted to slide upon a fixed rod 21. The clutch shifter 16 is actuated to shift the clutch in one direction or the other by a spring 22 whichsurrounds the rod 21 and is interposed between two sleeves 23 and 24, mounted to slide freely u on the rod and en gagin the inner sides 0 the bosses 19 and 20. he'spring is compressed, and thus distorted and rendered active to operate the clutch shifter by a sliding casing 25 which substantially incloses the spring and is provided with cylindrical ends fitted to slide within bores formed in the inner sides of the hubs 19 and 20. The ends of the easing 25 surround the sleeves 23 and 24 and are provided with internal shoulders 26 and 27 arranged to engage flanges 28 and 29 on the inner ends of the sleeves. The casing '25 is moved in one direction or the other to compress and distort the spring 22 through a reversing lever 29, the lower end of which is connected by a link 30 with the casing and the up er end of which is rovided with a prqecting lug 31 arrange in the path of the do 32 and 33 which are ad- ]ustably secure upon a bar 34 on the work table. When the casing 25 is moved in either direction to compress the spring, the spring is restrained by one or the other of two latches 35 and 36 which are arranged to engage stop shoulders 37 and 38 on the clutch shifter frame 19. The latches are operated to. release the spring after it has been sufficiently compressed to effect a sudden shifting of the clutch by cam surfaces 39 and 40 ormed on the sliding casing 25 and arranged to engage the inner ends of the latches 35 and 36.

Assuming thatthe parts are in the position indicated in the drawings, the clutch 11 will be in engagement with the clutch member 9 and the table will be moving toward the left in Fig. 1. When the dog 32 engages the lever 29 the spring distorting slide 25 will be moved toward the right. and through the spring clutch shifter 16 will also be moved toward the right until the movement of the clutch shifter is arrested by the engagement of the stop shoulder 37 with the shoulder on the latch 35. During the continued movement of the slide 25 the spring will be compressed and rendered active to shift the clutch, the spring being restrained by the latch 35. After the spring has been compressed to the proper degree the cam 39 on the slide 25 will lift the latch 35, thus releasing the spring and clutch shifter so that the clutch will be suddenly shifted from engagement with the clutch member 9 into engagement with the clutch member 10, thus reversing the movement of the table. The table will now move in the opposite direction until the dog 33 engages the reversing lever 29, when the slide 25 will be moved in the opposite direction to compress and release the s ring which during th1s movement of the slide is restrained by the latch 36 until it has been 22 and sleeve 23, the

compressed, after which the latch will be lifted by the cam 40 to release the spring and clutch shifter.

It is frequently desirable to stop the table of the grinding machine at either end of its travel, and the machine illustrated is provided with mechanism for conveniently securing this result which forms a part of the invention. As shown, this means comprises a stop block 41 which is pivotally supported on the-end of a slide 42'and isarranged to coiiperate with two stop shoulders 43 and 44 formed on a plate which is secured to the clutch shifter 16. During the 1 normal running of the machine the slide 42 is withdrawn so that the stop block 41 is inactive. If it is desired to stop the table when it reaches the end of its travel in the direction in which it may be moving, the

position, so that the table feeding mech-- anism will be disconnected from the driving shaft 12. If the table is moving in the opposite direction, or toward the right, when the slide is advanced, the stop block 41 will strike against the stop 43 and swing into position with its right end in the path of the stop 44, so that the movementof the clutch will be arrested in mid position when the clutch shifting spring is compressed and released by the action of the dog 33 on the reversing lever 29. v

When the movement of the table is arrested and the automatic'feed thrown out, it is frequently desirable to move the table manually and in accordance with the present invention the slide 42 is connected with a lever through which a hand feed is rendered active or inactive. As shown, the slide 42 is connected with the lower end of an arm 45 which is secured to one end of a rock shaft 46. A lever 47 is connected to the other end of the rock shaft and is also connected by a pivoted block 48 with the hub of a hand wheel 49. The hand wheel is loosely mountedupon a sleeve 50 and is rovided with a clutch member 51 adapte to engage a clutch member 52 secured to a feed shaft 53. The inner end of the feed shaft carries a pinion 54 which is connected with a pinion 55 on the shaft of the rack gear 4 through a gear- 56 indicated in dotted lines in Fig. 1. When the lever 47 is moved to render the stop block 41 active, the hand wheel is moved on the sleeve 50 to engage than? the clutch members 51 and 52, so that the,

table may be moved by operating the hand wheel. By moving the lever n theopposite directlon the hand wheel may be disengaged from the feed shaft 53. and. the same movement withdraws the stop block 41 and throws the automatic feed and reversing mechanism into action.

In order that the -parts'of the clutch shifting mechanism may be readily assembled and placed. in'positionon the front plate, it is preferred to mount the rod 21wh1ch earries these parts upon the centers 57 and 58, and to hold the center 58 in place by a set screw 59 engaging a conical groove 60 in the center, so that the center may be withdrawn to enable the insertion or removal of the rod and parts carried thereby.

While it is preferred to employ the specific construction and arrangement of parts shown and described, owing to its compactness and simplicity, it will be understood that this construction is not essential to the broader features of the invention but may be varied and modified as found desirable or best suited to the construction of the machine in which the invention is to be embodied.

Having explained the nature and object of the invention, what is claimed is:

1. Reversing mechanism, having, in combination, reversing devices, a single spring connected to operate the reversing devices, means forgiving the spring a like distortion throughout its length to shift the reversing devices in either direction, and devices for restraining and releasing the spring.

2. Reversing mechanism, having, in combination, reversing devices, a spring connected to operate the reversing devices, means for giving the spring a like distortion throughout its length in either of two directions, and devices for restraining and releasing the spring when distorted In either direction.

3. Reversing mechanism, having, in combination, reversing devices, a spring connected to operate the reversing devices, mechanism for compressing the spring throughout its length from either end, and devices for restraining and releasing the spring.

4. Reversing mechanism, having, in combination, reversing devices, including a shifter, a spring connected to move the shifter in opposite directions, a spring distorting device, means for moving the sprin' distorting device in opposite directions, an

' devices forrestraining opposite ends of the distorting device in opposite directions and r spring during the movement of the spring for releasing the spring to actuate the shifter.

5. Reversing mechanism, having, in combination, a reversing clutch, a clutch shifter,

aspr', for mot the'shifter in either direction, a device for the spring thron hout its w .from either end, .atches or restraining the t durng its QOIHEI'WSIOH, and means or operat- 1 the late es to release the sp 6. versmg meeha, having, binat on, a reversing .cliuteh, a clutch shifting frame provided with. oppo hubs, a.

spring interposed between the hubs, a spring compressing device arranged to act on either of the spring, means for moving the device in opposite directions, latches for preventing movement of theshifting frame'by the spring, and means for releasing the latches after the spring has been compressed;

7. Reversing-mechanism having, in combination, areversingclutc a clutchshifting framehavin opposed hubs, a rod on which the hubs s ide, a spring between the hubs, sleeves between the ends of the spring and the hubs, a spring compressor connected to move the sleeves, latches for preventing movement of the shifting frame by the spring, and means for moving the spring compressor in opposite directions and for alternately in opposite directions.

9. Reversing mechanism, having, in combination, a reciprocating member, mechanism for reciprocating the same, including'a reversing clutch, a clutch shifter, a spring connected to operate the shifter, a device for distorting the spring, reversing dogs mov-.

ing with the reciprocating member, connections through which the dogs move the spring distorting device, latches for restraining the spring during the initial movement of the spring distorting device in either direction, and means for releasing the latches after the spring has been distorted.

10. Reversing mechanism, having, in combination, a reciprocating member, mechanism for reciprocating the same, including a reversing clutch, a clutch shifterprovided with stop shoulders, a stop block arranged to engage one or the other of said shoulders and arrest the clutch in mid position, a hand feeding mechanism for the reciprocating member, and manually operated means for renderin the hand feeding mechanism and stop bloc simultaneously active or inactive.

11. Reversing mechanism, having, in combination, a reve,

shifter, a springconnected to move the shifter in opposite directions, a spring distorting device means for moving the spring distorting device in oplposite directions, devices for restraining t e spring during the movement of the distorting devices in either direction, and for releasing the spring to actuate the shifter, 'stop shoulders on the g device including a shifter, and a stop block movable into the 10 path of one or the other of the sto shoulders and arranged to arrest the cih mid position.

tch in HERBERT E. TOWNSEND.

Witnesses:

W. T. LIDDALL, H. A. W. HAYWARD. 

